1 /* Copyright (C) 2007-2016 B.A.T.M.A.N. contributors: 2 * 3 * Marek Lindner, Simon Wunderlich 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of version 2 of the GNU General Public 7 * License as published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it will be useful, but 10 * WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 * General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, see <http://www.gnu.org/licenses/>. 16 */ 17 18 #include "routing.h" 19 #include "main.h" 20 21 #include <linux/atomic.h> 22 #include <linux/byteorder/generic.h> 23 #include <linux/compiler.h> 24 #include <linux/errno.h> 25 #include <linux/etherdevice.h> 26 #include <linux/if_ether.h> 27 #include <linux/jiffies.h> 28 #include <linux/kref.h> 29 #include <linux/netdevice.h> 30 #include <linux/printk.h> 31 #include <linux/rculist.h> 32 #include <linux/rcupdate.h> 33 #include <linux/skbuff.h> 34 #include <linux/spinlock.h> 35 #include <linux/stddef.h> 36 37 #include "bitarray.h" 38 #include "bridge_loop_avoidance.h" 39 #include "distributed-arp-table.h" 40 #include "fragmentation.h" 41 #include "hard-interface.h" 42 #include "icmp_socket.h" 43 #include "network-coding.h" 44 #include "originator.h" 45 #include "packet.h" 46 #include "send.h" 47 #include "soft-interface.h" 48 #include "translation-table.h" 49 50 static int batadv_route_unicast_packet(struct sk_buff *skb, 51 struct batadv_hard_iface *recv_if); 52 53 /** 54 * _batadv_update_route - set the router for this originator 55 * @bat_priv: the bat priv with all the soft interface information 56 * @orig_node: orig node which is to be configured 57 * @recv_if: the receive interface for which this route is set 58 * @neigh_node: neighbor which should be the next router 59 * 60 * This function does not perform any error checks 61 */ 62 static void _batadv_update_route(struct batadv_priv *bat_priv, 63 struct batadv_orig_node *orig_node, 64 struct batadv_hard_iface *recv_if, 65 struct batadv_neigh_node *neigh_node) 66 { 67 struct batadv_orig_ifinfo *orig_ifinfo; 68 struct batadv_neigh_node *curr_router; 69 70 orig_ifinfo = batadv_orig_ifinfo_get(orig_node, recv_if); 71 if (!orig_ifinfo) 72 return; 73 74 rcu_read_lock(); 75 curr_router = rcu_dereference(orig_ifinfo->router); 76 if (curr_router && !kref_get_unless_zero(&curr_router->refcount)) 77 curr_router = NULL; 78 rcu_read_unlock(); 79 80 /* route deleted */ 81 if ((curr_router) && (!neigh_node)) { 82 batadv_dbg(BATADV_DBG_ROUTES, bat_priv, 83 "Deleting route towards: %pM\n", orig_node->orig); 84 batadv_tt_global_del_orig(bat_priv, orig_node, -1, 85 "Deleted route towards originator"); 86 87 /* route added */ 88 } else if ((!curr_router) && (neigh_node)) { 89 batadv_dbg(BATADV_DBG_ROUTES, bat_priv, 90 "Adding route towards: %pM (via %pM)\n", 91 orig_node->orig, neigh_node->addr); 92 /* route changed */ 93 } else if (neigh_node && curr_router) { 94 batadv_dbg(BATADV_DBG_ROUTES, bat_priv, 95 "Changing route towards: %pM (now via %pM - was via %pM)\n", 96 orig_node->orig, neigh_node->addr, 97 curr_router->addr); 98 } 99 100 if (curr_router) 101 batadv_neigh_node_put(curr_router); 102 103 /* increase refcount of new best neighbor */ 104 if (neigh_node && !kref_get_unless_zero(&neigh_node->refcount)) 105 neigh_node = NULL; 106 107 spin_lock_bh(&orig_node->neigh_list_lock); 108 /* curr_router used earlier may not be the current orig_ifinfo->router 109 * anymore because it was dereferenced outside of the neigh_list_lock 110 * protected region. After the new best neighbor has replace the current 111 * best neighbor the reference counter needs to decrease. Consequently, 112 * the code needs to ensure the curr_router variable contains a pointer 113 * to the replaced best neighbor. 114 */ 115 curr_router = rcu_dereference_protected(orig_ifinfo->router, true); 116 117 rcu_assign_pointer(orig_ifinfo->router, neigh_node); 118 spin_unlock_bh(&orig_node->neigh_list_lock); 119 batadv_orig_ifinfo_put(orig_ifinfo); 120 121 /* decrease refcount of previous best neighbor */ 122 if (curr_router) 123 batadv_neigh_node_put(curr_router); 124 } 125 126 /** 127 * batadv_update_route - set the router for this originator 128 * @bat_priv: the bat priv with all the soft interface information 129 * @orig_node: orig node which is to be configured 130 * @recv_if: the receive interface for which this route is set 131 * @neigh_node: neighbor which should be the next router 132 */ 133 void batadv_update_route(struct batadv_priv *bat_priv, 134 struct batadv_orig_node *orig_node, 135 struct batadv_hard_iface *recv_if, 136 struct batadv_neigh_node *neigh_node) 137 { 138 struct batadv_neigh_node *router = NULL; 139 140 if (!orig_node) 141 goto out; 142 143 router = batadv_orig_router_get(orig_node, recv_if); 144 145 if (router != neigh_node) 146 _batadv_update_route(bat_priv, orig_node, recv_if, neigh_node); 147 148 out: 149 if (router) 150 batadv_neigh_node_put(router); 151 } 152 153 /** 154 * batadv_window_protected - checks whether the host restarted and is in the 155 * protection time. 156 * @bat_priv: the bat priv with all the soft interface information 157 * @seq_num_diff: difference between the current/received sequence number and 158 * the last sequence number 159 * @seq_old_max_diff: maximum age of sequence number not considered as restart 160 * @last_reset: jiffies timestamp of the last reset, will be updated when reset 161 * is detected 162 * @protection_started: is set to true if the protection window was started, 163 * doesn't change otherwise. 164 * 165 * Return: 166 * 0 if the packet is to be accepted. 167 * 1 if the packet is to be ignored. 168 */ 169 int batadv_window_protected(struct batadv_priv *bat_priv, s32 seq_num_diff, 170 s32 seq_old_max_diff, unsigned long *last_reset, 171 bool *protection_started) 172 { 173 if (seq_num_diff <= -seq_old_max_diff || 174 seq_num_diff >= BATADV_EXPECTED_SEQNO_RANGE) { 175 if (!batadv_has_timed_out(*last_reset, 176 BATADV_RESET_PROTECTION_MS)) 177 return 1; 178 179 *last_reset = jiffies; 180 if (protection_started) 181 *protection_started = true; 182 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, 183 "old packet received, start protection\n"); 184 } 185 186 return 0; 187 } 188 189 bool batadv_check_management_packet(struct sk_buff *skb, 190 struct batadv_hard_iface *hard_iface, 191 int header_len) 192 { 193 struct ethhdr *ethhdr; 194 195 /* drop packet if it has not necessary minimum size */ 196 if (unlikely(!pskb_may_pull(skb, header_len))) 197 return false; 198 199 ethhdr = eth_hdr(skb); 200 201 /* packet with broadcast indication but unicast recipient */ 202 if (!is_broadcast_ether_addr(ethhdr->h_dest)) 203 return false; 204 205 /* packet with broadcast sender address */ 206 if (is_broadcast_ether_addr(ethhdr->h_source)) 207 return false; 208 209 /* create a copy of the skb, if needed, to modify it. */ 210 if (skb_cow(skb, 0) < 0) 211 return false; 212 213 /* keep skb linear */ 214 if (skb_linearize(skb) < 0) 215 return false; 216 217 return true; 218 } 219 220 /** 221 * batadv_recv_my_icmp_packet - receive an icmp packet locally 222 * @bat_priv: the bat priv with all the soft interface information 223 * @skb: icmp packet to process 224 * 225 * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP 226 * otherwise. 227 */ 228 static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv, 229 struct sk_buff *skb) 230 { 231 struct batadv_hard_iface *primary_if = NULL; 232 struct batadv_orig_node *orig_node = NULL; 233 struct batadv_icmp_header *icmph; 234 int res, ret = NET_RX_DROP; 235 236 icmph = (struct batadv_icmp_header *)skb->data; 237 238 switch (icmph->msg_type) { 239 case BATADV_ECHO_REPLY: 240 case BATADV_DESTINATION_UNREACHABLE: 241 case BATADV_TTL_EXCEEDED: 242 /* receive the packet */ 243 if (skb_linearize(skb) < 0) 244 break; 245 246 batadv_socket_receive_packet(icmph, skb->len); 247 break; 248 case BATADV_ECHO_REQUEST: 249 /* answer echo request (ping) */ 250 primary_if = batadv_primary_if_get_selected(bat_priv); 251 if (!primary_if) 252 goto out; 253 254 /* get routing information */ 255 orig_node = batadv_orig_hash_find(bat_priv, icmph->orig); 256 if (!orig_node) 257 goto out; 258 259 /* create a copy of the skb, if needed, to modify it. */ 260 if (skb_cow(skb, ETH_HLEN) < 0) 261 goto out; 262 263 icmph = (struct batadv_icmp_header *)skb->data; 264 265 ether_addr_copy(icmph->dst, icmph->orig); 266 ether_addr_copy(icmph->orig, primary_if->net_dev->dev_addr); 267 icmph->msg_type = BATADV_ECHO_REPLY; 268 icmph->ttl = BATADV_TTL; 269 270 res = batadv_send_skb_to_orig(skb, orig_node, NULL); 271 if (res != NET_XMIT_DROP) 272 ret = NET_RX_SUCCESS; 273 274 break; 275 default: 276 /* drop unknown type */ 277 goto out; 278 } 279 out: 280 if (primary_if) 281 batadv_hardif_put(primary_if); 282 if (orig_node) 283 batadv_orig_node_put(orig_node); 284 return ret; 285 } 286 287 static int batadv_recv_icmp_ttl_exceeded(struct batadv_priv *bat_priv, 288 struct sk_buff *skb) 289 { 290 struct batadv_hard_iface *primary_if = NULL; 291 struct batadv_orig_node *orig_node = NULL; 292 struct batadv_icmp_packet *icmp_packet; 293 int ret = NET_RX_DROP; 294 295 icmp_packet = (struct batadv_icmp_packet *)skb->data; 296 297 /* send TTL exceeded if packet is an echo request (traceroute) */ 298 if (icmp_packet->msg_type != BATADV_ECHO_REQUEST) { 299 pr_debug("Warning - can't forward icmp packet from %pM to %pM: ttl exceeded\n", 300 icmp_packet->orig, icmp_packet->dst); 301 goto out; 302 } 303 304 primary_if = batadv_primary_if_get_selected(bat_priv); 305 if (!primary_if) 306 goto out; 307 308 /* get routing information */ 309 orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->orig); 310 if (!orig_node) 311 goto out; 312 313 /* create a copy of the skb, if needed, to modify it. */ 314 if (skb_cow(skb, ETH_HLEN) < 0) 315 goto out; 316 317 icmp_packet = (struct batadv_icmp_packet *)skb->data; 318 319 ether_addr_copy(icmp_packet->dst, icmp_packet->orig); 320 ether_addr_copy(icmp_packet->orig, primary_if->net_dev->dev_addr); 321 icmp_packet->msg_type = BATADV_TTL_EXCEEDED; 322 icmp_packet->ttl = BATADV_TTL; 323 324 if (batadv_send_skb_to_orig(skb, orig_node, NULL) != NET_XMIT_DROP) 325 ret = NET_RX_SUCCESS; 326 327 out: 328 if (primary_if) 329 batadv_hardif_put(primary_if); 330 if (orig_node) 331 batadv_orig_node_put(orig_node); 332 return ret; 333 } 334 335 int batadv_recv_icmp_packet(struct sk_buff *skb, 336 struct batadv_hard_iface *recv_if) 337 { 338 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); 339 struct batadv_icmp_header *icmph; 340 struct batadv_icmp_packet_rr *icmp_packet_rr; 341 struct ethhdr *ethhdr; 342 struct batadv_orig_node *orig_node = NULL; 343 int hdr_size = sizeof(struct batadv_icmp_header); 344 int ret = NET_RX_DROP; 345 346 /* drop packet if it has not necessary minimum size */ 347 if (unlikely(!pskb_may_pull(skb, hdr_size))) 348 goto out; 349 350 ethhdr = eth_hdr(skb); 351 352 /* packet with unicast indication but broadcast recipient */ 353 if (is_broadcast_ether_addr(ethhdr->h_dest)) 354 goto out; 355 356 /* packet with broadcast sender address */ 357 if (is_broadcast_ether_addr(ethhdr->h_source)) 358 goto out; 359 360 /* not for me */ 361 if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest)) 362 goto out; 363 364 icmph = (struct batadv_icmp_header *)skb->data; 365 366 /* add record route information if not full */ 367 if ((icmph->msg_type == BATADV_ECHO_REPLY || 368 icmph->msg_type == BATADV_ECHO_REQUEST) && 369 (skb->len >= sizeof(struct batadv_icmp_packet_rr))) { 370 if (skb_linearize(skb) < 0) 371 goto out; 372 373 /* create a copy of the skb, if needed, to modify it. */ 374 if (skb_cow(skb, ETH_HLEN) < 0) 375 goto out; 376 377 icmph = (struct batadv_icmp_header *)skb->data; 378 icmp_packet_rr = (struct batadv_icmp_packet_rr *)icmph; 379 if (icmp_packet_rr->rr_cur >= BATADV_RR_LEN) 380 goto out; 381 382 ether_addr_copy(icmp_packet_rr->rr[icmp_packet_rr->rr_cur], 383 ethhdr->h_dest); 384 icmp_packet_rr->rr_cur++; 385 } 386 387 /* packet for me */ 388 if (batadv_is_my_mac(bat_priv, icmph->dst)) 389 return batadv_recv_my_icmp_packet(bat_priv, skb); 390 391 /* TTL exceeded */ 392 if (icmph->ttl < 2) 393 return batadv_recv_icmp_ttl_exceeded(bat_priv, skb); 394 395 /* get routing information */ 396 orig_node = batadv_orig_hash_find(bat_priv, icmph->dst); 397 if (!orig_node) 398 goto out; 399 400 /* create a copy of the skb, if needed, to modify it. */ 401 if (skb_cow(skb, ETH_HLEN) < 0) 402 goto out; 403 404 icmph = (struct batadv_icmp_header *)skb->data; 405 406 /* decrement ttl */ 407 icmph->ttl--; 408 409 /* route it */ 410 if (batadv_send_skb_to_orig(skb, orig_node, recv_if) != NET_XMIT_DROP) 411 ret = NET_RX_SUCCESS; 412 413 out: 414 if (orig_node) 415 batadv_orig_node_put(orig_node); 416 return ret; 417 } 418 419 /** 420 * batadv_check_unicast_packet - Check for malformed unicast packets 421 * @bat_priv: the bat priv with all the soft interface information 422 * @skb: packet to check 423 * @hdr_size: size of header to pull 424 * 425 * Check for short header and bad addresses in given packet. 426 * 427 * Return: negative value when check fails and 0 otherwise. The negative value 428 * depends on the reason: -ENODATA for bad header, -EBADR for broadcast 429 * destination or source, and -EREMOTE for non-local (other host) destination. 430 */ 431 static int batadv_check_unicast_packet(struct batadv_priv *bat_priv, 432 struct sk_buff *skb, int hdr_size) 433 { 434 struct ethhdr *ethhdr; 435 436 /* drop packet if it has not necessary minimum size */ 437 if (unlikely(!pskb_may_pull(skb, hdr_size))) 438 return -ENODATA; 439 440 ethhdr = eth_hdr(skb); 441 442 /* packet with unicast indication but broadcast recipient */ 443 if (is_broadcast_ether_addr(ethhdr->h_dest)) 444 return -EBADR; 445 446 /* packet with broadcast sender address */ 447 if (is_broadcast_ether_addr(ethhdr->h_source)) 448 return -EBADR; 449 450 /* not for me */ 451 if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest)) 452 return -EREMOTE; 453 454 return 0; 455 } 456 457 /** 458 * batadv_find_router - find a suitable router for this originator 459 * @bat_priv: the bat priv with all the soft interface information 460 * @orig_node: the destination node 461 * @recv_if: pointer to interface this packet was received on 462 * 463 * Return: the router which should be used for this orig_node on 464 * this interface, or NULL if not available. 465 */ 466 struct batadv_neigh_node * 467 batadv_find_router(struct batadv_priv *bat_priv, 468 struct batadv_orig_node *orig_node, 469 struct batadv_hard_iface *recv_if) 470 { 471 struct batadv_algo_ops *bao = bat_priv->bat_algo_ops; 472 struct batadv_neigh_node *first_candidate_router = NULL; 473 struct batadv_neigh_node *next_candidate_router = NULL; 474 struct batadv_neigh_node *router, *cand_router = NULL; 475 struct batadv_neigh_node *last_cand_router = NULL; 476 struct batadv_orig_ifinfo *cand, *first_candidate = NULL; 477 struct batadv_orig_ifinfo *next_candidate = NULL; 478 struct batadv_orig_ifinfo *last_candidate; 479 bool last_candidate_found = false; 480 481 if (!orig_node) 482 return NULL; 483 484 router = batadv_orig_router_get(orig_node, recv_if); 485 486 if (!router) 487 return router; 488 489 /* only consider bonding for recv_if == BATADV_IF_DEFAULT (first hop) 490 * and if activated. 491 */ 492 if (!(recv_if == BATADV_IF_DEFAULT && atomic_read(&bat_priv->bonding))) 493 return router; 494 495 /* bonding: loop through the list of possible routers found 496 * for the various outgoing interfaces and find a candidate after 497 * the last chosen bonding candidate (next_candidate). If no such 498 * router is found, use the first candidate found (the previously 499 * chosen bonding candidate might have been the last one in the list). 500 * If this can't be found either, return the previously chosen 501 * router - obviously there are no other candidates. 502 */ 503 rcu_read_lock(); 504 last_candidate = orig_node->last_bonding_candidate; 505 if (last_candidate) 506 last_cand_router = rcu_dereference(last_candidate->router); 507 508 hlist_for_each_entry_rcu(cand, &orig_node->ifinfo_list, list) { 509 /* acquire some structures and references ... */ 510 if (!kref_get_unless_zero(&cand->refcount)) 511 continue; 512 513 cand_router = rcu_dereference(cand->router); 514 if (!cand_router) 515 goto next; 516 517 if (!kref_get_unless_zero(&cand_router->refcount)) { 518 cand_router = NULL; 519 goto next; 520 } 521 522 /* alternative candidate should be good enough to be 523 * considered 524 */ 525 if (!bao->bat_neigh_is_similar_or_better(cand_router, 526 cand->if_outgoing, 527 router, recv_if)) 528 goto next; 529 530 /* don't use the same router twice */ 531 if (last_cand_router == cand_router) 532 goto next; 533 534 /* mark the first possible candidate */ 535 if (!first_candidate) { 536 kref_get(&cand_router->refcount); 537 kref_get(&cand->refcount); 538 first_candidate = cand; 539 first_candidate_router = cand_router; 540 } 541 542 /* check if the loop has already passed the previously selected 543 * candidate ... this function should select the next candidate 544 * AFTER the previously used bonding candidate. 545 */ 546 if (!last_candidate || last_candidate_found) { 547 next_candidate = cand; 548 next_candidate_router = cand_router; 549 break; 550 } 551 552 if (last_candidate == cand) 553 last_candidate_found = true; 554 next: 555 /* free references */ 556 if (cand_router) { 557 batadv_neigh_node_put(cand_router); 558 cand_router = NULL; 559 } 560 batadv_orig_ifinfo_put(cand); 561 } 562 rcu_read_unlock(); 563 564 /* last_bonding_candidate is reset below, remove the old reference. */ 565 if (orig_node->last_bonding_candidate) 566 batadv_orig_ifinfo_put(orig_node->last_bonding_candidate); 567 568 /* After finding candidates, handle the three cases: 569 * 1) there is a next candidate, use that 570 * 2) there is no next candidate, use the first of the list 571 * 3) there is no candidate at all, return the default router 572 */ 573 if (next_candidate) { 574 batadv_neigh_node_put(router); 575 576 /* remove references to first candidate, we don't need it. */ 577 if (first_candidate) { 578 batadv_neigh_node_put(first_candidate_router); 579 batadv_orig_ifinfo_put(first_candidate); 580 } 581 router = next_candidate_router; 582 orig_node->last_bonding_candidate = next_candidate; 583 } else if (first_candidate) { 584 batadv_neigh_node_put(router); 585 586 /* refcounting has already been done in the loop above. */ 587 router = first_candidate_router; 588 orig_node->last_bonding_candidate = first_candidate; 589 } else { 590 orig_node->last_bonding_candidate = NULL; 591 } 592 593 return router; 594 } 595 596 static int batadv_route_unicast_packet(struct sk_buff *skb, 597 struct batadv_hard_iface *recv_if) 598 { 599 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); 600 struct batadv_orig_node *orig_node = NULL; 601 struct batadv_unicast_packet *unicast_packet; 602 struct ethhdr *ethhdr = eth_hdr(skb); 603 int res, hdr_len, ret = NET_RX_DROP; 604 605 unicast_packet = (struct batadv_unicast_packet *)skb->data; 606 607 /* TTL exceeded */ 608 if (unicast_packet->ttl < 2) { 609 pr_debug("Warning - can't forward unicast packet from %pM to %pM: ttl exceeded\n", 610 ethhdr->h_source, unicast_packet->dest); 611 goto out; 612 } 613 614 /* get routing information */ 615 orig_node = batadv_orig_hash_find(bat_priv, unicast_packet->dest); 616 617 if (!orig_node) 618 goto out; 619 620 /* create a copy of the skb, if needed, to modify it. */ 621 if (skb_cow(skb, ETH_HLEN) < 0) 622 goto out; 623 624 /* decrement ttl */ 625 unicast_packet = (struct batadv_unicast_packet *)skb->data; 626 unicast_packet->ttl--; 627 628 switch (unicast_packet->packet_type) { 629 case BATADV_UNICAST_4ADDR: 630 hdr_len = sizeof(struct batadv_unicast_4addr_packet); 631 break; 632 case BATADV_UNICAST: 633 hdr_len = sizeof(struct batadv_unicast_packet); 634 break; 635 default: 636 /* other packet types not supported - yet */ 637 hdr_len = -1; 638 break; 639 } 640 641 if (hdr_len > 0) 642 batadv_skb_set_priority(skb, hdr_len); 643 644 res = batadv_send_skb_to_orig(skb, orig_node, recv_if); 645 646 /* translate transmit result into receive result */ 647 if (res == NET_XMIT_SUCCESS) { 648 /* skb was transmitted and consumed */ 649 batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD); 650 batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES, 651 skb->len + ETH_HLEN); 652 653 ret = NET_RX_SUCCESS; 654 } else if (res == NET_XMIT_POLICED) { 655 /* skb was buffered and consumed */ 656 ret = NET_RX_SUCCESS; 657 } 658 659 out: 660 if (orig_node) 661 batadv_orig_node_put(orig_node); 662 return ret; 663 } 664 665 /** 666 * batadv_reroute_unicast_packet - update the unicast header for re-routing 667 * @bat_priv: the bat priv with all the soft interface information 668 * @unicast_packet: the unicast header to be updated 669 * @dst_addr: the payload destination 670 * @vid: VLAN identifier 671 * 672 * Search the translation table for dst_addr and update the unicast header with 673 * the new corresponding information (originator address where the destination 674 * client currently is and its known TTVN) 675 * 676 * Return: true if the packet header has been updated, false otherwise 677 */ 678 static bool 679 batadv_reroute_unicast_packet(struct batadv_priv *bat_priv, 680 struct batadv_unicast_packet *unicast_packet, 681 u8 *dst_addr, unsigned short vid) 682 { 683 struct batadv_orig_node *orig_node = NULL; 684 struct batadv_hard_iface *primary_if = NULL; 685 bool ret = false; 686 u8 *orig_addr, orig_ttvn; 687 688 if (batadv_is_my_client(bat_priv, dst_addr, vid)) { 689 primary_if = batadv_primary_if_get_selected(bat_priv); 690 if (!primary_if) 691 goto out; 692 orig_addr = primary_if->net_dev->dev_addr; 693 orig_ttvn = (u8)atomic_read(&bat_priv->tt.vn); 694 } else { 695 orig_node = batadv_transtable_search(bat_priv, NULL, dst_addr, 696 vid); 697 if (!orig_node) 698 goto out; 699 700 if (batadv_compare_eth(orig_node->orig, unicast_packet->dest)) 701 goto out; 702 703 orig_addr = orig_node->orig; 704 orig_ttvn = (u8)atomic_read(&orig_node->last_ttvn); 705 } 706 707 /* update the packet header */ 708 ether_addr_copy(unicast_packet->dest, orig_addr); 709 unicast_packet->ttvn = orig_ttvn; 710 711 ret = true; 712 out: 713 if (primary_if) 714 batadv_hardif_put(primary_if); 715 if (orig_node) 716 batadv_orig_node_put(orig_node); 717 718 return ret; 719 } 720 721 static int batadv_check_unicast_ttvn(struct batadv_priv *bat_priv, 722 struct sk_buff *skb, int hdr_len) { 723 struct batadv_unicast_packet *unicast_packet; 724 struct batadv_hard_iface *primary_if; 725 struct batadv_orig_node *orig_node; 726 u8 curr_ttvn, old_ttvn; 727 struct ethhdr *ethhdr; 728 unsigned short vid; 729 int is_old_ttvn; 730 731 /* check if there is enough data before accessing it */ 732 if (!pskb_may_pull(skb, hdr_len + ETH_HLEN)) 733 return 0; 734 735 /* create a copy of the skb (in case of for re-routing) to modify it. */ 736 if (skb_cow(skb, sizeof(*unicast_packet)) < 0) 737 return 0; 738 739 unicast_packet = (struct batadv_unicast_packet *)skb->data; 740 vid = batadv_get_vid(skb, hdr_len); 741 ethhdr = (struct ethhdr *)(skb->data + hdr_len); 742 743 /* check if the destination client was served by this node and it is now 744 * roaming. In this case, it means that the node has got a ROAM_ADV 745 * message and that it knows the new destination in the mesh to re-route 746 * the packet to 747 */ 748 if (batadv_tt_local_client_is_roaming(bat_priv, ethhdr->h_dest, vid)) { 749 if (batadv_reroute_unicast_packet(bat_priv, unicast_packet, 750 ethhdr->h_dest, vid)) 751 batadv_dbg_ratelimited(BATADV_DBG_TT, 752 bat_priv, 753 "Rerouting unicast packet to %pM (dst=%pM): Local Roaming\n", 754 unicast_packet->dest, 755 ethhdr->h_dest); 756 /* at this point the mesh destination should have been 757 * substituted with the originator address found in the global 758 * table. If not, let the packet go untouched anyway because 759 * there is nothing the node can do 760 */ 761 return 1; 762 } 763 764 /* retrieve the TTVN known by this node for the packet destination. This 765 * value is used later to check if the node which sent (or re-routed 766 * last time) the packet had an updated information or not 767 */ 768 curr_ttvn = (u8)atomic_read(&bat_priv->tt.vn); 769 if (!batadv_is_my_mac(bat_priv, unicast_packet->dest)) { 770 orig_node = batadv_orig_hash_find(bat_priv, 771 unicast_packet->dest); 772 /* if it is not possible to find the orig_node representing the 773 * destination, the packet can immediately be dropped as it will 774 * not be possible to deliver it 775 */ 776 if (!orig_node) 777 return 0; 778 779 curr_ttvn = (u8)atomic_read(&orig_node->last_ttvn); 780 batadv_orig_node_put(orig_node); 781 } 782 783 /* check if the TTVN contained in the packet is fresher than what the 784 * node knows 785 */ 786 is_old_ttvn = batadv_seq_before(unicast_packet->ttvn, curr_ttvn); 787 if (!is_old_ttvn) 788 return 1; 789 790 old_ttvn = unicast_packet->ttvn; 791 /* the packet was forged based on outdated network information. Its 792 * destination can possibly be updated and forwarded towards the new 793 * target host 794 */ 795 if (batadv_reroute_unicast_packet(bat_priv, unicast_packet, 796 ethhdr->h_dest, vid)) { 797 batadv_dbg_ratelimited(BATADV_DBG_TT, bat_priv, 798 "Rerouting unicast packet to %pM (dst=%pM): TTVN mismatch old_ttvn=%u new_ttvn=%u\n", 799 unicast_packet->dest, ethhdr->h_dest, 800 old_ttvn, curr_ttvn); 801 return 1; 802 } 803 804 /* the packet has not been re-routed: either the destination is 805 * currently served by this node or there is no destination at all and 806 * it is possible to drop the packet 807 */ 808 if (!batadv_is_my_client(bat_priv, ethhdr->h_dest, vid)) 809 return 0; 810 811 /* update the header in order to let the packet be delivered to this 812 * node's soft interface 813 */ 814 primary_if = batadv_primary_if_get_selected(bat_priv); 815 if (!primary_if) 816 return 0; 817 818 ether_addr_copy(unicast_packet->dest, primary_if->net_dev->dev_addr); 819 820 batadv_hardif_put(primary_if); 821 822 unicast_packet->ttvn = curr_ttvn; 823 824 return 1; 825 } 826 827 /** 828 * batadv_recv_unhandled_unicast_packet - receive and process packets which 829 * are in the unicast number space but not yet known to the implementation 830 * @skb: unicast tvlv packet to process 831 * @recv_if: pointer to interface this packet was received on 832 * 833 * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP 834 * otherwise. 835 */ 836 int batadv_recv_unhandled_unicast_packet(struct sk_buff *skb, 837 struct batadv_hard_iface *recv_if) 838 { 839 struct batadv_unicast_packet *unicast_packet; 840 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); 841 int check, hdr_size = sizeof(*unicast_packet); 842 843 check = batadv_check_unicast_packet(bat_priv, skb, hdr_size); 844 if (check < 0) 845 return NET_RX_DROP; 846 847 /* we don't know about this type, drop it. */ 848 unicast_packet = (struct batadv_unicast_packet *)skb->data; 849 if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) 850 return NET_RX_DROP; 851 852 return batadv_route_unicast_packet(skb, recv_if); 853 } 854 855 int batadv_recv_unicast_packet(struct sk_buff *skb, 856 struct batadv_hard_iface *recv_if) 857 { 858 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); 859 struct batadv_unicast_packet *unicast_packet; 860 struct batadv_unicast_4addr_packet *unicast_4addr_packet; 861 u8 *orig_addr; 862 struct batadv_orig_node *orig_node = NULL; 863 int check, hdr_size = sizeof(*unicast_packet); 864 enum batadv_subtype subtype; 865 bool is4addr; 866 867 unicast_packet = (struct batadv_unicast_packet *)skb->data; 868 unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data; 869 870 is4addr = unicast_packet->packet_type == BATADV_UNICAST_4ADDR; 871 /* the caller function should have already pulled 2 bytes */ 872 if (is4addr) 873 hdr_size = sizeof(*unicast_4addr_packet); 874 875 /* function returns -EREMOTE for promiscuous packets */ 876 check = batadv_check_unicast_packet(bat_priv, skb, hdr_size); 877 878 /* Even though the packet is not for us, we might save it to use for 879 * decoding a later received coded packet 880 */ 881 if (check == -EREMOTE) 882 batadv_nc_skb_store_sniffed_unicast(bat_priv, skb); 883 884 if (check < 0) 885 return NET_RX_DROP; 886 if (!batadv_check_unicast_ttvn(bat_priv, skb, hdr_size)) 887 return NET_RX_DROP; 888 889 /* packet for me */ 890 if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) { 891 if (is4addr) { 892 subtype = unicast_4addr_packet->subtype; 893 batadv_dat_inc_counter(bat_priv, subtype); 894 895 /* Only payload data should be considered for speedy 896 * join. For example, DAT also uses unicast 4addr 897 * types, but those packets should not be considered 898 * for speedy join, since the clients do not actually 899 * reside at the sending originator. 900 */ 901 if (subtype == BATADV_P_DATA) { 902 orig_addr = unicast_4addr_packet->src; 903 orig_node = batadv_orig_hash_find(bat_priv, 904 orig_addr); 905 } 906 } 907 908 if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb, 909 hdr_size)) 910 goto rx_success; 911 if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, 912 hdr_size)) 913 goto rx_success; 914 915 batadv_interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size, 916 orig_node); 917 918 rx_success: 919 if (orig_node) 920 batadv_orig_node_put(orig_node); 921 922 return NET_RX_SUCCESS; 923 } 924 925 return batadv_route_unicast_packet(skb, recv_if); 926 } 927 928 /** 929 * batadv_recv_unicast_tvlv - receive and process unicast tvlv packets 930 * @skb: unicast tvlv packet to process 931 * @recv_if: pointer to interface this packet was received on 932 * 933 * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP 934 * otherwise. 935 */ 936 int batadv_recv_unicast_tvlv(struct sk_buff *skb, 937 struct batadv_hard_iface *recv_if) 938 { 939 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); 940 struct batadv_unicast_tvlv_packet *unicast_tvlv_packet; 941 unsigned char *tvlv_buff; 942 u16 tvlv_buff_len; 943 int hdr_size = sizeof(*unicast_tvlv_packet); 944 int ret = NET_RX_DROP; 945 946 if (batadv_check_unicast_packet(bat_priv, skb, hdr_size) < 0) 947 return NET_RX_DROP; 948 949 /* the header is likely to be modified while forwarding */ 950 if (skb_cow(skb, hdr_size) < 0) 951 return NET_RX_DROP; 952 953 /* packet needs to be linearized to access the tvlv content */ 954 if (skb_linearize(skb) < 0) 955 return NET_RX_DROP; 956 957 unicast_tvlv_packet = (struct batadv_unicast_tvlv_packet *)skb->data; 958 959 tvlv_buff = (unsigned char *)(skb->data + hdr_size); 960 tvlv_buff_len = ntohs(unicast_tvlv_packet->tvlv_len); 961 962 if (tvlv_buff_len > skb->len - hdr_size) 963 return NET_RX_DROP; 964 965 ret = batadv_tvlv_containers_process(bat_priv, false, NULL, 966 unicast_tvlv_packet->src, 967 unicast_tvlv_packet->dst, 968 tvlv_buff, tvlv_buff_len); 969 970 if (ret != NET_RX_SUCCESS) 971 ret = batadv_route_unicast_packet(skb, recv_if); 972 else 973 consume_skb(skb); 974 975 return ret; 976 } 977 978 /** 979 * batadv_recv_frag_packet - process received fragment 980 * @skb: the received fragment 981 * @recv_if: interface that the skb is received on 982 * 983 * This function does one of the three following things: 1) Forward fragment, if 984 * the assembled packet will exceed our MTU; 2) Buffer fragment, if we till 985 * lack further fragments; 3) Merge fragments, if we have all needed parts. 986 * 987 * Return: NET_RX_DROP if the skb is not consumed, NET_RX_SUCCESS otherwise. 988 */ 989 int batadv_recv_frag_packet(struct sk_buff *skb, 990 struct batadv_hard_iface *recv_if) 991 { 992 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); 993 struct batadv_orig_node *orig_node_src = NULL; 994 struct batadv_frag_packet *frag_packet; 995 int ret = NET_RX_DROP; 996 997 if (batadv_check_unicast_packet(bat_priv, skb, 998 sizeof(*frag_packet)) < 0) 999 goto out; 1000 1001 frag_packet = (struct batadv_frag_packet *)skb->data; 1002 orig_node_src = batadv_orig_hash_find(bat_priv, frag_packet->orig); 1003 if (!orig_node_src) 1004 goto out; 1005 1006 /* Route the fragment if it is not for us and too big to be merged. */ 1007 if (!batadv_is_my_mac(bat_priv, frag_packet->dest) && 1008 batadv_frag_skb_fwd(skb, recv_if, orig_node_src)) { 1009 ret = NET_RX_SUCCESS; 1010 goto out; 1011 } 1012 1013 batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_RX); 1014 batadv_add_counter(bat_priv, BATADV_CNT_FRAG_RX_BYTES, skb->len); 1015 1016 /* Add fragment to buffer and merge if possible. */ 1017 if (!batadv_frag_skb_buffer(&skb, orig_node_src)) 1018 goto out; 1019 1020 /* Deliver merged packet to the appropriate handler, if it was 1021 * merged 1022 */ 1023 if (skb) 1024 batadv_batman_skb_recv(skb, recv_if->net_dev, 1025 &recv_if->batman_adv_ptype, NULL); 1026 1027 ret = NET_RX_SUCCESS; 1028 1029 out: 1030 if (orig_node_src) 1031 batadv_orig_node_put(orig_node_src); 1032 1033 return ret; 1034 } 1035 1036 int batadv_recv_bcast_packet(struct sk_buff *skb, 1037 struct batadv_hard_iface *recv_if) 1038 { 1039 struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); 1040 struct batadv_orig_node *orig_node = NULL; 1041 struct batadv_bcast_packet *bcast_packet; 1042 struct ethhdr *ethhdr; 1043 int hdr_size = sizeof(*bcast_packet); 1044 int ret = NET_RX_DROP; 1045 s32 seq_diff; 1046 u32 seqno; 1047 1048 /* drop packet if it has not necessary minimum size */ 1049 if (unlikely(!pskb_may_pull(skb, hdr_size))) 1050 goto out; 1051 1052 ethhdr = eth_hdr(skb); 1053 1054 /* packet with broadcast indication but unicast recipient */ 1055 if (!is_broadcast_ether_addr(ethhdr->h_dest)) 1056 goto out; 1057 1058 /* packet with broadcast sender address */ 1059 if (is_broadcast_ether_addr(ethhdr->h_source)) 1060 goto out; 1061 1062 /* ignore broadcasts sent by myself */ 1063 if (batadv_is_my_mac(bat_priv, ethhdr->h_source)) 1064 goto out; 1065 1066 bcast_packet = (struct batadv_bcast_packet *)skb->data; 1067 1068 /* ignore broadcasts originated by myself */ 1069 if (batadv_is_my_mac(bat_priv, bcast_packet->orig)) 1070 goto out; 1071 1072 if (bcast_packet->ttl < 2) 1073 goto out; 1074 1075 orig_node = batadv_orig_hash_find(bat_priv, bcast_packet->orig); 1076 1077 if (!orig_node) 1078 goto out; 1079 1080 spin_lock_bh(&orig_node->bcast_seqno_lock); 1081 1082 seqno = ntohl(bcast_packet->seqno); 1083 /* check whether the packet is a duplicate */ 1084 if (batadv_test_bit(orig_node->bcast_bits, orig_node->last_bcast_seqno, 1085 seqno)) 1086 goto spin_unlock; 1087 1088 seq_diff = seqno - orig_node->last_bcast_seqno; 1089 1090 /* check whether the packet is old and the host just restarted. */ 1091 if (batadv_window_protected(bat_priv, seq_diff, 1092 BATADV_BCAST_MAX_AGE, 1093 &orig_node->bcast_seqno_reset, NULL)) 1094 goto spin_unlock; 1095 1096 /* mark broadcast in flood history, update window position 1097 * if required. 1098 */ 1099 if (batadv_bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1)) 1100 orig_node->last_bcast_seqno = seqno; 1101 1102 spin_unlock_bh(&orig_node->bcast_seqno_lock); 1103 1104 /* check whether this has been sent by another originator before */ 1105 if (batadv_bla_check_bcast_duplist(bat_priv, skb)) 1106 goto out; 1107 1108 batadv_skb_set_priority(skb, sizeof(struct batadv_bcast_packet)); 1109 1110 /* rebroadcast packet */ 1111 batadv_add_bcast_packet_to_list(bat_priv, skb, 1); 1112 1113 /* don't hand the broadcast up if it is from an originator 1114 * from the same backbone. 1115 */ 1116 if (batadv_bla_is_backbone_gw(skb, orig_node, hdr_size)) 1117 goto out; 1118 1119 if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb, hdr_size)) 1120 goto rx_success; 1121 if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, hdr_size)) 1122 goto rx_success; 1123 1124 /* broadcast for me */ 1125 batadv_interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size, 1126 orig_node); 1127 1128 rx_success: 1129 ret = NET_RX_SUCCESS; 1130 goto out; 1131 1132 spin_unlock: 1133 spin_unlock_bh(&orig_node->bcast_seqno_lock); 1134 out: 1135 if (orig_node) 1136 batadv_orig_node_put(orig_node); 1137 return ret; 1138 } 1139